This alcohol is processed from special kind of glutinous rice, a specialty of Hoành Bồ.

It is not pounded, but boiled and then fermented. After achieving a
degree of ripeness, it is soaked with certain forest leaves, becoming
alcohol. It has both a sweet and sour taste, excites the appetite and
is a good refreshing drink, especially during the summer.

Another strong point is that, according to locals, if you get drunk off
of it you’ll wake up the next morning without a hangover and want to
drink more.